U.S. patent number 7,168,717 [Application Number 11/046,310] was granted by the patent office on 2007-01-30 for high clearance vehicle suspension with twin spindles for transferring steering torque.
This patent grant is currently assigned to Deere & Company. Invention is credited to Jack Conan Anderson, William Allen Brett, Brandon Cy Carlson, Marvin Anthony Maiwald, Thomas Mark Wubben.
United States Patent |
7,168,717 |
Wubben , et al. |
January 30, 2007 |
High clearance vehicle suspension with twin spindles for
transferring steering torque
Abstract
An independent strut suspension utilizes upright twin spindles
and a spindle cap linked to the spindles that translates vertically
along the spindles as the suspension moves over uneven terrain. An
upright strut shaft is mounted in a strut journal for axial and
rotational movement with respect to the journal. A steering arm is
connected for rotation about the strut shaft axis, and the strut
shaft moves axially with respect to the steering arm as the frame
moves over the uneven terrain. The upright spindles connect the
steering arm and the upper mount, and a spring is supported between
the upper end of the strut shaft and the upper mount and provides
cushioning for the wheel support as the strut shaft moves axially
in the journal.
Inventors: |
Wubben; Thomas Mark (Ankeny,
IA), Maiwald; Marvin Anthony (Ankeny, IA), Carlson;
Brandon Cy (Ankeny, IA), Anderson; Jack Conan (Madrid,
IA), Brett; William Allen (Polk City, IA) |
Assignee: |
Deere & Company (Moline,
IL)
|
Family
ID: |
36097204 |
Appl.
No.: |
11/046,310 |
Filed: |
January 28, 2005 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060170176 A1 |
Aug 3, 2006 |
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Current U.S.
Class: |
280/124.127;
280/93.502; 280/93.51; 280/124.157; 280/124.154 |
Current CPC
Class: |
B60B
35/001 (20130101); B62D 49/0678 (20130101); B60B
35/1054 (20130101); B60B 35/109 (20130101); B60G
3/01 (20130101); B60G 11/27 (20130101); B62D
7/06 (20130101); B60B 35/008 (20130101); B60G
2200/44 (20130101); B60G 2202/413 (20130101); B60G
2204/126 (20130101); B60G 2204/15 (20130101); B60G
2204/4232 (20130101); B60G 2204/4502 (20130101); B60G
2300/083 (20130101); B60G 2300/40 (20130101); B60Y
2200/22 (20130101) |
Current International
Class: |
B60G
3/01 (20060101) |
Field of
Search: |
;280/124.127,124.154,124.155,124.157,92,93.502,93.505 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Dickson; Paul N.
Assistant Examiner: Spisich; George D
Claims
The invention claimed is:
1. In an agricultural sprayer having a frame adapted for forward
movement over uneven terrain, a suspension system comprising: an
upright strut shaft having a strut shaft axis and upper and lower
ends; an axle having a strut journal mounting the upright strut
shaft for axial movement along the strut shaft axis and for
rotational movement therein; a wheel support connected to the lower
end of the strut shaft; a steering arm connected for rotation
generally about the strut shaft axis, wherein the strut shaft moves
axially in the direction of the strut shaft axis with respect to
the steering arm as the frame moves over the uneven terrain; an
upper spring support; first and second upright spindles connecting
the steering arm and the upper spring support; a spring supported
between the upper end of the strut shaft and the upper spring
support and providing cushioning for the wheel support as the strut
shaft moves axially in the journal; and a spindle bracket fixed to
the strut shaft and connected to the spindles for vertical movement
with respect to the spindles as the strut shaft moves axially, the
spindles and spindle bracket constraining the strut shaft for
rotational movement with the steering arm for steering the wheel
support while facilitating relative axial movement in the direction
of the strut shaft axis between the upper end of the strut shaft
and the steering arm.
2. The suspension system as set forth in claim 1 including a
steering cylinder having an effective cylinder length supported at
one end from the axle and connected at an opposite end to the
steering arm, wherein the steering arm maintains the steering
cylinder in generally a constant vertical position as the strut
shaft moves axially so that the effective cylinder length is
unaffected by strut shaft movement in the direction of the strut
shaft axis.
3. The suspension system as set forth in claim 1 wherein the
steering arm is rotatably mounted in the strut journal.
4. The suspension system as set forth in claim 3 wherein the
steering arm comprises a journal area extending into the strut
journal.
5. The suspension system as set forth in claim 1 wherein the spring
comprises an airbag compressed between the strut shaft and the
upper spring support.
6. The suspension system as set forth in claim 1 wherein the
upright spindles and strut shaft are parallel to each other.
7. In an agricultural implement having a frame adapted for forward
movement over uneven terrain, a high clearance suspension system
comprising: an upright strut shaft having a strut shaft axis and
upper and lower ends; an axle having a strut journal mounting the
upright strut shaft for axial movement along an upright strut shaft
axis and for rotational movement therein; a wheel support connected
to the lower end of the strut shaft; a steering arm connected to
the journal mounting for rotation with respect thereto generally
about the strut shaft axis, wherein the strut shaft moves axially
in the direction of the upright strut shaft axis with respect to
the steering arm as the frame moves over the uneven terrain, the
steering arm remaining relatively fixed in the vertical direction
with respect to the journal; an upper spring support; upright
spindles connecting the steering arm and the upper spring support;
a pneumatic spring supported between the upper end of the strut
shaft and the upper spring support and providing cushioning for the
wheel support as the strut shaft moves axially in the journal; and
a spindle bracket fixed to the strut shaft and slidably received
over the spindles for vertical movement with respect to the
spindles and the steering arm as the strut shaft moves axially, the
spindles and spindle bracket constraining the strut shaft for
rotational movement with the steering arm for steering the wheel
support while facilitating relative axial movement in the direction
of the upright strut shaft axis between the spindle bracket and the
spindles.
8. The suspension system as set forth in claim 7 including a
steering cylinder having an effective cylinder length and supported
at one end from the journal and connected at an opposite end to the
steering arm, wherein the steering arm maintains the steering
cylinder in generally a constant vertical position as the strut
shaft moves axially in the direction of the upright strut shaft
axis so that the effective cylinder length is unaffected by the
axial strut shaft movement.
Description
FIELD OF THE INVENTION
The present invention relates generally to agricultural high
clearance vehicles and, more specifically, to suspension and
steering systems for implements such as self-propelled
sprayers.
BACKGROUND OF THE INVENTION
Suspensions for high clearance agricultural vehicles such as the
John Deere 4720 Sprayer utilize a linkage to translate torque from
a steering cylinder input to the suspension spindle. Such a linkage
is shown, for example, in commonly assigned U.S. Pat. No. 5,597,172
and includes a pneumatic spring supported above a strut shaft which
is received within a strut journal connected to an adjustable axle.
A scissors assembly located above the axle maintains wheel steer
while facilitating vertical movement of the strut shaft within the
journal. On non-steerable wheels, the lower end of the scissors
assembly is connected to the journal to maintain a preselected
wheel orientation. For steerable wheels, the lower end of the
scissors assembly is connected to a hydraulic steering structure
which allows axle adjustments for varying wheel tread. Although the
scissors structure functions well to keep the steering cylinder in
plane during vertical motion of the strut shaft, such an assembly
is relatively expensive and requires maintenance.
Another type of suspension system includes a steering cylinder
attached at one end to the chassis and at the other end to the
suspension. Although such a system can be simpler and less costly
than the scissors assembly, the effective cylinder length will
change with suspension travel causing undesirable changes in the
steering angle and steering control problems. In systems wherein:
the cylinder mounted to move vertically with the suspension, other
problems can arise such as bracket complexity and cost, cylinder
clearance and cylinder hose routing requirements, and added
potential for cylinder and cylinder hose damage.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an
improved suspension for a high clearance vehicle such as a
self-propelled agricultural sprayer. It is another object to
provide such a suspension which overcomes most or all of the
aforementioned problems.
It is a another object to provide an improved suspension for a high
clearance vehicle which eliminates steering angle and steering
control problems common with at least some of the previously
available suspension systems. It is a further object to provide
such a suspension which obviates need for scissors linkages or for
steering cylinders that move vertically with the suspension. It is
another object to provide such a suspension having a steering
cylinder which is maintained generally in a consistent plane as the
suspension moves over uneven terrain.
It is still another object to provide an improved suspension for a
high clearance vehicle which has improved serviceability and
reliability but yet is lower in cost than many previously available
suspensions. It is a further object to provide such a suspension
which is also more compact and lighter in weight than at least many
previously available suspensions.
An independent strut suspension is described which utilizes upright
twin spindles and a spindle cap linked to the spindles that
translates vertically along the spindles as the suspension moves
over uneven terrain. An upright strut shaft is mounted in a strut
journal for axial and rotational movement with respect to the
journal. A steering arm is connected for rotation about the strut
shaft axis, and the strut shaft moves axially with respect to the
steering arm. The upright spindles connect the steering arm and the
upper mount, and a spring is supported between the upper end of the
strut shaft and the upper mount and provides cushioning for the
wheel support as the strut shaft moves axially in the journal. The
spindle cap is rotationally fixed relative to the strut shaft and
connected to the spindles for vertical movement with respect to the
spindles as the strut shaft moves axially. The spindles and spindle
bracket constrain the strut shaft for rotational movement with the
steering arm for steering the wheel support while facilitating
relative axial movement between the spindle bracket and the
spindles.
The suspension eliminates scissors structures and moving cylinder
supports. The torque load is carried through the spindles by
allowing the suspension spindle cap casting to be linked to the
spindles while still allowing the cap to translate axially along
the steering spindles.
The suspension relatively light in weight and less complex and
expensive than systems requiring scissors structures or steering
cylinders that move with the suspension. Maintenance requirements
are reduced, and the design is more compact and less subject to
cylinder and hose damage. The steering cylinder can be attached at
one end directly to the frame and is maintained in a plane to avoid
unwanted effective cylinder length changes and steering control
problems.
These and other objects, features and advantages of the present
invention will become apparent in view of the drawings and the
description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an outside perspective view of a portion of high
clearance agricultural vehicle showing an independent strut
suspension connected to the vehicle frame.
FIG. 2 is an inside perspective view of the suspension shown in
FIG. 1.
FIG. 3 is a top view, partially in section, of the suspension of
FIG. 1.
FIG. 4 is a sectional view of the suspension of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, therein is shown a portion of a high
clearance agricultural vehicle 10 such as a self-propelled
agricultural field sprayer 10 having a main frame 12. The sprayer
may be generally of the type shown and described in the
aforementioned U.S. Pat. No. 5,597,172.
Transversely adjustable wheel axle assemblies, one of which is
shown at 14, are slidably received in tubular frame members 16 and
support a steerable suspension assembly 18. The suspension assembly
18 includes a tube 22 having an inner end slidably received by the
member 16. The tube 22 is connected to a hydraulic tread adjust
cylinder 24 for adjusting the vehicle tread. A knee joint 28 is
connected to the outermost end of the tube 22 and includes an
upright journal area 30 slidably and rotatably mounting an upright
strut shaft or suspension spindle 32 having a shaft axis 32a (FIG.
4). The lower end of the strut shaft 32 is fixed to a wheel support
and motor housing 34 which carries a hydraulically driven and
steerable ground engaging wheel (not shown). The upper end of the
shaft 32 is fixed to an upper mount or spindle cap 36, and an
airbag 40 or other spring type of device connected to the top of
the upper mount 36 provides spring cushioning for the suspension
spindle and housing 34.
A steering arm 44 is rotatably mounted at the journal area 30 in an
enlarged bore 46 and slidably receives a central portion of the
suspension spindle 32. The strut shaft 32 is free to move axially
relative to the steering arm 44 so that the vertical position of
the steering arm 44 remains constant relative to the knee joint 28.
A steering cylinder arm 50 is fixed to the knee joint 28 by bolts
52 and extends in a fore-and-aft direction therefrom to a base end
connection at 54 to a steering cylinder 56. The cylinder 56 extends
from the base end connection at 54 to a rod end connection at 58
with a radially projecting steering member 64 on the steering arm
44.
The steering arm 44 supports the lower ends of first and second
upright steering spindles 70 and 72 generally parallel to the axis
32a outwardly of the airbag 40. The spindles 70 and 72 are fixed to
the steering arm 44 by bolts 76 (FIG. 4) and a taper lock and
extend upwardly to a location above the airbag 40. An uppermost
spindle spacer and spring support 80 is bolted to the tops of the
spindles 70 and 72, and the airbag 40 is contained between the
upper mount 36 and the support 80. The upper mount 36 includes
guides or spindle bracket 82 and 84 slidably received over the
outer circumference of the spindles 70 and 72 for constraining the
upper mount 36 for rotation in unison with the steering arm 44. The
upper end of the strut shaft 32 is connected to the upper mount 36
by a taper lock and a bolt and washer assembly 90 and is keyed at
92 for constraining the strut shaft 32 for rotation with the upper
mount 36. Therefore, steering torque is transferred from the
steering arm 44 through the spindles 70 and 72 and through the
upper mount 36 to the strut shaft 32. As the steering cylinder 56
is extended and retracted, the strut shaft 32 will rotate in the
journal area 30 about the axis 32a with the steering arm 44 to
steer the housing 34 and attached drive wheel structure.
The steering spindles 70 and 72 thereby constrain the strut shaft
32 to maintain a constant angular relationship with the steering
arm 44 while permitting the strut shaft 32 to move up and down in
the journal area 30 and in the bore in the steering arm 44 to
compress and relax the airbag 40 as the wheel structure moves over
the surface of the ground or as the weight supported by the wheel
structure changes. Bumpers 102 and 104 (FIG. 4) provide protection
for the suspension at the extreme positions of the strut shaft
32.
Having described the preferred embodiment, it will become apparent
that various modifications can be made without departing from the
scope of the invention as defined in the accompanying claims.
* * * * *